Rotary pumps or compressors



March 1 F. w. MQCOMBEE ROTARY PUMPS OR COMPRESSORS Filed April 13. 1956 INVENTOR fisvz-w/ck/ /7' Kb/1315 BY q r ATTOR 5% ,United. States Patent 2,879,913 ROTARY PUMPS 0R COMPRESSORS Frederick Walter McCombie, London, England, assignor to Megator Pumps & Compressors Limited,London, England This invention relates to rotary pumps, compressors or other machines, wherein access to the interior of the machine necessitates removal of a comparatively heavy cover. The invention is, for example, applicable to pumps or compressors forming the subject of prior Patents Nos. 2,561,808, 2,561,809, 2,561,810, 2,612,846, 2,728,615 and 2,750,896. Such rotary pumps or compressors comprise a casing having inlet and outlet connections and provided with bearings at its opposite ends carrying a rotatable shaft in turn carrying one or more eccentrics, each revolvable in an associated displacement chamber or shoe which is reciprocable over a ported plate, the plate and shoe or shoes being formed with co-operating ports which under the reciprocating action of the shoe or shoes control the flow of fluid to and from the interior of the shoe which in conjunction with the eccentric forms the displacement chamber proper.

In this particular type of rotary pump or compressor the ported plate is in the form of a comparatively heavy hollow casting which closes the pump casing on one side and which necessarily has to be removed for access to the shoe or shoes. Such pumps or compressors may be of quite large size, particularly in the case of a pump or compressor containing more than one eccentric and consequently the removal of this casting hereinafter referred to as a cover is extremely difficult because of its great weight. The chief object of the invention is to facilitate removal of the cover and also its replacement when required.

The invention consists broadly in providing the pump or compressor casing with a beam from which the cover plate is supported in a slidable manner, the beam being slidably associated with the casing so that normally it will occupy an unobtrusive position, but when required for use in connection with the removal of the cover can be slidden outwardly into a position in which it will form a cantilever support for the cover, thereby enabling the latter when its associated securing nuts have been released to be slidden lengthwise of the cantilever beam and whilst supported by the beam moved into a position in which free access can be obtained through the then open side of the casing to the shoes and their associated eccentrics or other mechanism contained within the casing.

It will be appreciated that the cover is usually secured in position by nuts in screw-threaded connection with studs carried by the casing, which studs project through borings in the cover and that as a result of the beam taking the weight of the cover during the latters removal, the risk of jamming of the cover on the studs during removal and replacement will be very much reduced.

Referring to the drawings:

Figure 1 is a perspective view of a pump, the cover being shown supported by the beam; and

Figure 2 is a side elevation, the cover and beam being shown in their normal positions.

2,879,913 Patented Mar. 31,

ice

In the construction illustrated, the beam takes: the form of two bars or girders I placed on edge and spaced apart by suitable distance pieces 2 at their ends, the beam. being slidable along a horizontal surface onv the upper part of the casing 3 ofthe pump, compressor 01' other machine. The casing carries two upstanding studs 4 which are spaced apart and pass upwardly between the components of the beam, the studsbeing provided with nuts 5 so that normally the beam can be loclged in its normal inner unobtrusive position shown in FigureZ. The cover 6 is also provided with a single stud 7' which projects upwardly between the beam components and is provided with a nut 8 by means of which; the cover can be suspended from the beam.

The cover is held in position by means. of a number of nuts 9 which engage studs 10 which pass through suitable holes arranged around the edge of the cover 6 and to remove the cover from the casing it is necessary to remove these nuts and to slide the cover oif the studs. The procedure adopted when removing the cover plate is to slacken oil the three nuts 5 and 8 arranged above the beam, slide the beam outwardly into the position shown in Figure 1 in which it projects forwardly of the casing and then tighten down the two nuts 5 which hold the beam on the casing, the beam then providing a cantilever support along which the cover can be slidden when its associated nuts 9 have been removed. In this connection it is desirable before sliding the cover to tighten up slightly the nut 8 associated with the stud 7 which passes through the beam into the cover so that the weight of the cover will be taken by this stud and the beam instead of by the studs 10 which normally hold the cover in position on the casing and to release the nut when the cover is in position so that it can be bolted up solidly to the casing.

The cover can then be slidden forwardly along the beam and finally turned about the axis of its supporting stud so as to give better access to the interior of the machine.

When it is desired to replace the cover the latter is re-engaged with the studs and its associated supporting stud nut again adjusted if necessary to enable the comparatively heavy cover to be slidden into its original position. Finally, the beam is returned to its inoperative position and the two holding down nuts tightened up to secure the beam in its inoperative position.

I claim:

1. A rotary pump, compressor or other machine comprising a heavy metal casing having an opening in one side and securing means on said one side and spaced around said opening, a heavy metal cover for closing said opening and having securing means spaced around its edge portions and respectively registrable with said casing securing means for securing said cover to said one side, a slideway on the top of said casing and extending perpendicularly of said one side, an elongated beam slidably mounted longitudinally on said slideway, means on said casing for guiding said beam through a limited movement longitudinally and releasably clamping said beam in selected position on said slideway, and means secured to the top of said cover in balancing relation thereto and adjustably suspending said cover from said beam for alignment of said cover and easing securing means, said beam being of a length not materially exceeding the combined depth of said cover and said casing but when extended permitting sliding of said cover outwardly from said one side of said casing to the limit imposed by said guide means with said cover at the extended end of said beam and spaced from said opening to enable access to the interior of said casing.

2. A rotary pump, compressor or other machine com- 3 prising .a heavy metal casing having an opening in one side, a plurality of studs extending from said casing side and spaced around said opening, a heavy metal cover for closing said opening and having bores spaced around its edge for receiving said studs to secure said cover in closed position, a slideway on the top of said casing and extending perpendicularly of said one side, a pair of spaced studs extending upwardly from said slideway with their axes disposed'in a plane perpendicular to said one side, an elongated beam having a slot extending longitudinally thereof and mounted on said slideway with said pair of studs extending upwardly through the slot thereof, nuts on said pair of studs and retaining said beam thereon and releasably clamping said beam on said slideway, a stud on the top of said cover in balancing relation thereto and extending upwardly through said beam slot-, and a nut on said cover stud suspending said cover from said beam and adjustably suspending said cover from said beam for alignment of said cover bores with References Cited in the file of this patent UNITED STATES PATENTS 918,222 Theurer Apr. 13, 1909 1,244,222 McCaskell Oct. 23, 1917 2,027,083 Baer Ian. 7, 1936 2,556,578 Dohm June 12, 1951 2,583,085 Campbell Jan. 22, 1952 

